;XIncludeFile "E:\pbi\getAngle.pbi"
;{ ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~\ E:\pbi\getAngle.pbi
        ; getAngle.pbi
        
        
        Procedure.f getAngle(mx,my, px,py, mode.l=1)
        ; returns the angle of a line going from point
        ; [mx,my] to point [px,py] in radian
        ; mode=1 (default):
        ; pointing to the right means 0 degrees
        ; pointing to the top means 90 degrees, ect
        ; [math y-axis]
        ; mode=-1:
        ; pointing to the right means 0 degrees
        ; pointing to the bottom means 90 degrees, ect
        ; [screen y-axis.]
        
          Static xd.l, yd.l, alpha.f
          xd=px-mx
          yd=py-my
          
          If xd>0
            If     yd<0 :: alpha=         ATan(-yd / xd )
            ElseIf yd>=0 :: alpha= 2*#PI - ATan( yd / xd )
            EndIf
          ElseIf xd<0
            If     yd<0 :: alpha=   #PI - ATan(-yd /-xd )
            ElseIf yd>=0 :: alpha=   #PI + ATan( yd /-xd )
            EndIf
          ElseIf xd=0
            If     yd>0 : alpha=   #PI*1.5
            ElseIf yd<0 : alpha=   #PI*0.5
            EndIf
          EndIf
          If mode=-1
            alpha = 2*#PI-alpha
          EndIf
        ;   If Not Random(200)
        ;     Debug Str(xd) + " | " + Str(yd) + " | " + StrF(alpha)
        ;   EndIf
          ProcedureReturn alpha
        EndProcedure
        
        
        ; [...]
;}
;  ________________________________/ [end] E:\pbi\getAngle.pbi



Procedure rotateSprite(spr,aspr.d)
  Static xmax,ymax, x,y
  Static a.d, d.d
  Static i.l, k.l
  
  xmax=SpriteWidth(spr)-1
  ymax=SpriteHeight(spr)-1
  Dim p.l(xmax,ymax)
  
  StartDrawing(SpriteOutput(spr))
    For i=0 To xmax
      For k=0 To ymax
        a=getangle(xmax/2,ymax/2,i,k,-1)-aspr
        d=Sqr( (i-xmax/2)*(i-xmax/2) + (k-ymax/2)*(k-ymax/2) )
        x=xmax/2 + d*Cos(a)
        y=ymax/2 + d*Sin(a)
        If x>=0 And y>=0 And x<=xmax And y<=ymax
          p(i,k)=Point(x,y)
        EndIf
      Next
    Next
    For i=0 To xmax
      For k=0 To ymax
        Plot(i,k,p(i,k))
      Next
    Next
  StopDrawing()
EndProcedure





; InitSprite()
; ww=1100
; wh=800
; style | #PB_Window_ScreenCentered
; style | #PB_Window_SystemMenu
; style | #PB_Window_MinimizeGadget
; hWin=OpenWindow(0, 50,100,ww,wh, "",style)
; AddKeyboardShortcut(0,#PB_Shortcut_Escape,10)
; AddKeyboardShortcut(0,#PB_Shortcut_R,11)
; OpenWindowedScreen( hWin, 0,0,ww,wh, 0,0,0)
; 
; 
; ;LoadSprite(0,"E:\mo.bmp")
; UseJPEGImageDecoder()
; LoadSprite(0,"E:\GUCK\fractal-dd.jpg")
; CopySprite(0,1)
; 
; 
; Repeat
;   event=WaitWindowEvent(80)
;   em=EventMenu()
;   Select event
;     Case #PB_Event_CloseWindow
;       quit=1
;     Case #PB_Event_Menu
;       Select em
;       Case 10
;         quit=1
;       Case 11
;       EndSelect
;   EndSelect
;         CopySprite(0,1)
;         rotateSprite(1,getangle(0,0,WindowMouseX(0)-ww/2,WindowMouseY(0)-wh/2,-1))
;   DisplaySprite( 1, (ww-SpriteWidth(1))/2,(wh-SpriteHeight(1))/2 )
;   FlipBuffers()
;   ClearScreen($333333)
; Until quit












; IDE Options = PureBasic 4.20 Beta 3 (Windows - x86)
; CursorPosition = 16
; Folding = -
; HideErrorLog
; CompileSourceDirectory